Breaker bar and pulverizer assemblies for road rebuilding apparatus



Sept. 22, 1959 C. W, RAFFERTY ET AL 2,905,456

BREAKER BAR AND PULVERIZER ASSEMBLIES FOR ROAD REBUILDING APPARATUS Filed Aug. l5, 1955 5 Sheets-Sheet 1 Cac/L W. HFFE'RTY ROBERT 0. ,L5/551.5.

BY THE/l? ATTORNEYS.

HnRR/s, KnscH, Fos 'TER i HARR/s Sept. 22, 1959 c. w. RAFFERTY ETAL 2,905,456

BREAKER BAR AND PULVERIZER ASSEMBLIES FOR ROAD REBUILDING APPARATUS 5 Sheets-Sheet 2 Filed Aug. 15, 1955 Cac/1. W. PAFFERTY ROBERT D. LE/BsLe BY THE/R HTTONLYJ. HARRIS, K/ECH, FOSTER HARR/s Sept. 22, 1959 C, w, RAFFERTY ET AL 2,905,456

BREAKER BAR AND PULVERIZER ASSEMBLIES FOR ROAD REBUILDING APPARATUS Filed Aug. l5, 1955 l 5 SheetS-Shee'b 3 /NveA/ToRs. CEc/L, W. @Aff-Rw ROBERT 0.1.5/55/.5

BY THE/R HTTORNYS. HAR/ws, K/scH, F0575@ HARRIS Sept. 22, 1959 C, w RAFFERTY ETAL 2,905,456 I BREAKER BAR AND- PULVERIZER ASSEMBLIES FOR ROAD REBUILDING APPARATUS Filed Aug. l5, 1955 5 Sheets-Sheet 4' l BY THE/l? ATTORNEYS. HA RR/.s, Kleef-g FosTsR HHRR/s Sept. 22, 1959 C, w RAFFERTY ET AL 2,905,456

BREAKER BAR AND PULVERIZER ASSEMBLIES FOR ROAD REBUILDING APPARATUS Filed Aug. 15. 1955 5 Sheets-Sheet 5 Cac/L, W. RAF/fiery ROBERT D. L15/551.5'

BY THEIR ATTORNEYS. HA RR/s, Kleef-f, FosTt-,e Hmm/s United States Patent v2,905,456 Patented Sept. 22, 1959 Additional objects and the various features of the invention will become apparent to those skilled in this art 2,905,456

BREAKER BAR AND PULVERIZER ASSEMBLIES FOR ROAD REBUILDING APPARATUS Cecil W. Rafferty, North Hollywood, and Robert D. Leibsle, Van Nuys, Calif., assignors to lPettihone Wood Mfg. Co., North Hollywood, Calif., a 'corporation of Delaware f Application August '15, 1955, Serial No. 528,289

Claims. (Cl. 262-9) This invention relates to road-working equipment, and more particularly to machines which are especially adapted to tear up old oiled roads, macadam roads, and the like and prepare the old surfacing materials for use in reconstructing the roads.

The general object of the invention is to provide a machine of great efiiciency -which may be economically employed to reduce surfaces of old roads of the `indicated type to a size appropriate for use as at least a part of the road surfacing materials required to rebuild the road.

Many old road surfaces are constructed with materials well adapted for use in rebuilding or resurfacing those same roads. For example, materials may be reused which were originally employed in building oil macadam roads, oil-mix pavements, cemented gravel roads, hard base adobe or hard sand clay roads stabilized with emulsied asphalt or similar materials, and other old road surfaces capable of being torn up with breaker teeth or the like and appropriately pulverized. In addition, where such tearing up and pulverizing can be properly accomplished without disturbing unduly the road lfoundation or subgrade, excellent reconstructions may be made on the old foundations using the old sur-facing materials as constituents of the replacement surfaces.

It is, therefore, another object of this invention to produce road-working structures which will properly break up or tear up and pulverize the surface of old roads, and which will at the same time perform such functions without unduly disturbing the old road foundations or subgrades.

It is also an object of the invention to provide an apparatus of the indicated nature which will properly prepare 01d surfacing materials for reuse with a minimum number of trips up and down the roadway. Apparatus of this invention has, for example, properly pulverized old road surfacing materials of the above-indicated nature in only one or two trips and at a forward speed between about one and one-half miles to two miles per hour, and in practically no case have more than three trips been required.

upon reference to the following specification and the accompanying drawings wherein certain embodiments of j the invention are illustrated.

Referring to the drawings:

Fig. 1 is a side elevation of apparatus equipped with the improvements of this invention; f'

Fig. 2 is a view, partly in section and partly in Irear elevation, taken approximately on the line 2-2 of Fig. l;

Fig. 3 is a perspective view of a breaker bar and breaker tooth assembly;

Fig. 3A is a sectional detail of the breaker teeth assembly of Fig. 3 as indicated by the line .3A-3A;

Fig. 4 is a perspective View of a modified form of breaker bar assembly;

Fig. 4A is a Sectional detail on the line 4A--4A of Fig. 4;

Fig. 5 is a longitudinal vertical section through the rearl ward portion of the equipment of Fig. l, and on an enlarged scale, showing in cross section, as indicated by the line 5-5 of Fig. 2 the pulverizing rotor and the breaker bar structure;

Fig. 6 is an enlarged combined cross-sectional and elevational detail taken from the line `6 6 of Fig. 5 showing the mounting of one of the pulverizing plates or blades of the pulverizing rotor assembly seen in Fig. 2;

Fig. 7 is partially a longitudinal elevation and partially a longitudinal section from the line 7-7 of Fig. 6;

Fig. 8 is a longitudinal vertical lsection similar to that of Fig. 5 and showing a slight modification of structures of Fig. 5

Fig. 9 is an enlarged sectional and elevational view, similar to that of Fig. 6, and taken from the line 9,9 of Fig. 8;

Fig. 10 is a view similar to that of Fig. 7 as indicated by the line 1li- 10 of Fig. 9;

Fig. ll is a perspective view of a wedge employed for loosening the pulverizing blades from their mountings;

Fig. 12 is an enlarged longitudinal sect-ion similar to those of Figs. 5 and 8 and illustrating a modified form of pulverizing structure and arrangement; and

Fig. 13 is an elevational detail taken on the line 13.-13

of Fig. 12.

Referring first to Figs. 1 and 2, the apparatus shown comprises a main frame 10, two ground wheels 12, a breaker bar assembly embodying a plurality of transversely arranged breaker teeth 14 seen also in Fig. 3, a rotor 15 comprising pulverizing means, a shroud 16 enclosing the rotor 15, a power transmission mechanism generally indicated at 17, and a power plant 18 such asan internal combustion engine. The frame 10 is shown in the form of two channeled side rails 20 whose rearward portions support the rotor 15 and whose forward portions may converge as indicated in- Fig. l to form a It is a still further object of the invention to provide in a road pulverizing machine of the present type a rotary pulverizing mechanism which works directly upon the torn up or broken road surface materials as the surface tongue 22 to the forward end of which is secured a hitch n plateV 23 provided at its forward edge with a plurality of lbolt Lholes 24 for adjustably mounting a hitch ring is torn up by the breaker means and which is rotated at a relatively high speed to effect pulverizing while the apparatus as a whole moves forward at low speed.

It is also an object of the invention to provide for relative vertical adjustment of the breaking and pulverizing means with respect to the road surface being treated so that such penetration and `disintegration may be accomplished as is necessary in any individual instance.

Further objects are to provide novel means and arrangements for tearing up old road surfaces, for pulverizing the broken materials, and for replaceably mounting certain of said means.

25 through the medium of bolts 26. Y The wheels 12 are mounted upon stub axles 30 carried on the rearward ends of axle arms 31 whose forward ends are pivotally' mounted upon the frame 10 as by means of a cross shaft 32 which may be carried in brackets 32m mounted on the side rails A20. The position of each wheel 12 and the rearward end of its arm 31 with respectA to the frame 10 is independently adjustable through the medium of a hydraulic jack I for each arm 31. Each hydraulic jack includes a pivotal mounting 33 secured to the upper side of the rearward portion of the respective arm 31, the lower en d vof a piston rod 34 being pivotally connected to such mounting 33 and ythe otherv end extending upward into a cylinder 35 whose lower end is pivotally carried by a mounting 36 suitably secured to the upper portion of the adjacent side rail 20. These hydraulic jacks are controlled from a suitable valveassembly 37 through the 4medium ofvalve handles 38, the assembly 37 being carried, in the form illustrated, upon the upper end of a suitable standard 39 appropriately carried upon a top plate or other portion of the frame 10.

The rotor 15 is carried by la Vpair of spaced-pillow block bearings v40 (Fig. 2) ixed at the under side of theframe 10 as by means of brackets 41 welded to the respective channeled side rails 20. The rotor 15 comprises a drive shaft 42 whose ends are journaled in the bearings 40. The intermediate portion of the shaft 42 is squared, as seen at 42a in Figs. 5 and 8, for the purpose of xedly, but; removably, mounting pulverizing means thereon as presently to -be described. One end of the drive shaft 42 projects beyond its bearing 46, as indicated in Fig. 2, and receives on its extremity a sprocket 43 secured by a key 44. The sprocket 43 receives a drive chain 45 which is actuated bya sprocket 46 keyed upon the outer end of a power shaft 47 journaled in an appropriaterbearing 48 mounted on a bracket 49 carried by the frame 10. The power shaft 47 is connected by a shear coupling 50 to a power transmission mechanism 52 contained within a suitable housing 53 and actuated by gears 54a and a right-angularly Vdisposed shaft 54 which is energized through the medium of a clutch control lever 55 and a clutch` (not shown) contained within a clutch housing 56 and connected with the power plant 18. As illustrated, 4the sprockets 43 and 46 and the drive chain 45 may be enclosed by any suitable cover 57 which serves to guard these parts. Also, as seen in- Fig. l, an appropriately mounted idler 58 bearing against the chain 45 may be used, this idlerV being carried by an adjacent back plate 59 iixed to the mountings for the bearings 40 and 48.

The operative parts of the rotor 15, which act as pulverizing agents and are secured to the square section 42a! of the drive shaft 42, are in the form of two-piece removable rotor plates 60 (Figs. 5 vand 8) which extend radially from the square shaft portion 42a. Each half of each plate 60 is provided at each side with an axially extending hub portion 62 shaped to t the square shaft portion 42a. The hub portions 62 of the cooperating halves of each rotor plate 60 are secured together and bound upon the square shaft portion 42a by bolts 63. Since, as indicated in Fig. 5, Ithe bolts 63 are readily accessible, any rotor plate may be easily replaced in case of breakage or other injury, or, in case it is necessary to reduce the number of the rotor plates and attached mechanisms `to facilitate proper road working, the bolts 63 may be removed.

As best seen in Figs. and 8, each complete rotor A ing variable by adjustment.

plate is provided with four circumferentially directed and peripherally disposed, removable pulverizing blades 65 which serve to cut or crush and adequately break up the road surfacing material upon which the rotor operates. In addition to being removable and being tangentially or circumferentially directed, each pulverizing blade 65, which is usually flat, has an advancing square-cut rectangular end indicated at 66 which extends transversely ofthe blade and in parallelism with the axis of the rotor drive shaft 42, whereby to act as an advancing cutting edge during rotation ofthe pulverizing rotor 15. Each pulverizing blade 65 is mounted on its rotor plate 60 by means of a dove-tail joint provided by a longitudinally extending locking tongue 68 carried on the back of the blade and fitting into a circumferentially or tangentially directed complementary beveled groove or socket 69 in a tangential supporting head 70 fixed upon the outer extremity of a radially extending arm portion of the` respective rotor plate 60. The side portions of'the supporting head 70 extend laterally Va short distance from the two sides of the plate 60 to provide adequate width and bearing surface in the groove 69 for the mounting of the tongue 68 and its blade 65. In addition to its dove-tail construction, the resultant joint is also longitudinally tapered to produce a wedge shape narrowing rearward so that the trailing end of the blade 65 is Ywedged onto the head 70. Retention against longitudinal dislodgement of the bladel 65 is avoided by use of a hook -bolt 71 which has an offset arm orhook portion 71a received in a transverse pocket 72 in the trailing end of the blade, the shank of the bolt extending through lan outstanding ear 73 on the rear of the head Iand receiving on its outer end lock nuts 74 to be turned up against the earl to produce the wedge t.

As indicated in Figs. 2, 5 and 8 the pulverizing blades 65 of successive `rotor plates are arranged in a spiral or staggered pattern so that there is a circumferential spacing between Iadjacent blades, which may be in the order of 30, for example, or other appropriate spacing which will result in optimum pulverizing or torn-up road surfaces and delivery of such pulverized materials rearward. The exact elect may vary somewhat with the old road surfacing materials being treated and the exact disposition of the breaker teeth assembly carrying the breaker teeth 14 previously mentioned. Thus, in the particular arrangement shown in Fig. 5, the broken surfacing material is lifted up and fed to the advancing ends of the pulverizing plates 65 lat their lowermos-t position where only a narrow space is provided at the contact point with the surfacing materials between the advancing edges of the blades 65 and the uppermost portions of the breaker teeth assembly, whereas with the structure shown in Fig. 8, the uppermost portion of the breaker teeth assembly may be somewhat rearward of the axis of rotation and of the -lowest points of the pulverizing blades A65, whereby a bed of old surfacing material is providedy for action of the blades, this be- In both forms the shaft 42, 42a is rotated counterclockwise as indicated by the elongated peripheral arrows in Figs. 5 and 8, thereby bringing the cutting ends 66 into engagement with the raised broken road materials to pulverize them and throw them rearward in a relatively tine state of subdivision, as the whole 4apparatus moves forward. Since the gear ratio of the drive mechanism is such as to iml part, for example, about 450 revolutions per minute to the rotor 15 while the apparatus as a whole is movedl forward at about one and a half to two miles per hour', old surfacing of the oil macadam type is quite thoroughly broken up in a single'passage of the apparatus along the road, so that such pulverized materials may be again oiled, mixed with additional materials if required, and laid down again at the rear of the apparatus.

With respect to the mentioned breaker teeth Iassembly in the form shown in Figs. 3, 3A, 5 and 8, the teeth 14 are provided in a transverse series supported by a trans- Y verse supporting bar 75, which may also be termed a breaker bar 75 which is shown in an inclined position to direct the road-surfacing materials upward to the rotating pulverizing blades 65. The ends of the breaker bar 75 are anchored to the inner walls of supporting side plates 76 fixed in appropriate position as presently to be described so as to dispose the upper edge of the breaker bar 75 approximately in vertical alignment with the shaft 42. The forward, downwardly sloping wall 0f the breaker bar 75 fixedly carries a plurality of narrow positioning arms or brackets 78 which project forward and are tapered at their forward ends to enter corresponding pockets provided by the rea1ward portions of the breaker teeth 1=4 which in turn incline downward as they project forward whereby to penetrate, break and raise the old road surfacing materials as seen per portions of the breaker teeth 14 maybe provided by underlying small plate members 79 and side mem- I bers or guSsets 80 secured as by welding orY otherwise as required. In the particular form illustrated, the -small plates 79 and the gussets 8% are integral, having been bent from a single piece into a U-shaped channel fornation. This pocketing at the rearward portions of the breaker teeth 14 and the mounting thereof on the bracket arms 78 provide for easy removal of the teeth 14 when worn or damaged. Normal operation tends to wedge the teeth 14 onto the tapered forward ends of the arms 78 and appropriate through pins 82 guard against dislodgment.

In the form of Figs. 3 and 5, the breaker bar 75 is :reinforced by an appropriate angle construction which, as best seen in Fig. 5, includes a rear downwardly directed wall 83 which may be integral with the bar 75, there being an underlying intervening brace bar 84 welded at its opposite edges to the lowerportion `of the under face of the bar 75 and the lower inner face of the wall 83.- In this form, the supporting side plates 76 for the breaker bar assembly 75 are removably secured to depending longitudinally extending side walls 85 of the shroud 16 as by bolts 86. If required, the forward bolt 86 for each side plate 76 may serve as a pivot bolt and additional holes may be provided at 87 in the side walls 85 for vertical adjustment of the rearward bolt 86 to vary the height of the breaker bar 75.

In the form of the breaker bar assembly shown in Fig. 8, the same breaker bar 75 is employed as in the form of Figs. 3 'and 5 except that it extends somewhat farther rearward, and is braced by an angle iron 88 welded to the under side of the bar 75, the same bracket arms 78 being employed to receive the pocketed breaker teeth 14. Here, in order to eifect required adjustment of the height of the breaker bar 75, the rearward end of its mounting plate 76 in each instance is provided with an arcuate slot 89, the respective bolt 86 being relied upon to bind the respective plate 76 in adjusted position on a depending supporting side wall 85.

It is additionally desirable in both the forms of Figs. 5 and 8, and as is shown in Fig. 3, to provide at each side of the breaker bar vassembly a leading breaker tooth 90 which serves to define rough separation lines at the edges of the strip of old surface being torn up by the breaker teeth 14. Since the supporting side plates 76 are of heavy and strain resistant construction, the advancing breaker teeth 90 are desirably carried at the forward ends of such plates 76, this being accomplished by bracket arms 9,1 welded to the forward lower edge portions of the plates 76 and being removably received in pockets at the rearward ends of the teeth 90 exactly like those of the teeth 14. Here again through pins 82 are employed to insure the relationship. Instead of the advancing teeth 90 illustrated, it is often desirable, especially with some types of road surfacing, to employ a solid type of advancing tooth 92 seen in Figs. 4 and 12. This form of tooth is sloped downward to provide an inclined face 93 which is also tipped inward so as to direct material being sliced off inward toward the path of travel of the road-breaking means. This type of tooth is desirably somewhat blunt at its forward end, especially inasmuch as la blunt end tends to be maintained in practice in any event. As indicated, the rearward portion of lsuch tooth 92 is vertically shouldered so as to bear against the forward end of the respective side plate 76, the resultant inner end portion 92a' bearing against the inner wall of the blade 76 and being bolted, riveted, or welded thereto as preferred.

As also seen in Figs. 4 and 12, and in greater detail in Fig. 4A, a modified form of breaker bar assembly is desirably used, especially for some types of road surfaces, the breaker teeth 14 of the structure of Figs. 3, 5 and 8 and their mounting arms 7S, being replaced by a continuous transverse cutter bar 94 borne by the breaker bar 75. This breaker bar 75 is substantially the same as that seen in Fig. 5, with the preferable addition of an upstanding transversely extending stress bar 84a. The elongated cutter bar 94 is secured to the main plate of the breaker bar 75 by a series of bolts 95, the nuts of which are conveniently made accessible through corresponding holes 96 formed in the underlying brace bar 84, any resultant weakening produced by the forming of such holes 96 being overcome by lthe mentioned transverse stress bar 84a. The lower edge of the transverse cutter bar 94 is preferably beveled on its under side as indicated at 94a to facilitate penetration under the old road surfacing materials and the lifting thereof up along the outer and upper face of such cutter bar. It is desirable to bevel both edges of such cutter bar 94 so that it may be reversed and to provide duplicate sets of holes to receive the bolts 95, as illustrated. This form is usable not only in the relationship shown in Fig. 12, brut with any of the other forms shown in Figs.- 5 and 8;

It will be noted that there is a small difference between the pulverizing blades 65 of Figs. 5, 6 and 7 and those of Figs. 8, 9 and 10 and their mountings on the supporting heads 75. Thus, as seen in Fig. 6, the blade 65 is wider than its head 7G, whereas in Fig. 9, the blade 65 iS narrower than its head 7). Also, as seen in Fig. 7, the head 7@ extends rearward with respect to the supporting arm of its respective rotor plate 60, so that a wedgeshaped clearance passage 97 provided in the head 70 at the rear end of the respective blade 65 opens through to the back of the head 70, whereas in Figs. 9 and l0 the head 70 extends forward and a wedge-shaped clearance passage 98 at the rear end of the respective blade 65 divides at its inner end and opens at the sides of the main web of the respective rotor plate 60 so as to discharge any accumulating material. These tapered passages 97 and 98 are adapted to receive a forked wedge 99 shown separately in Fig. ll and indicated in spaced position in Fig. l0. This wedge 99 is used to loosen the tongues 68 of the blades 65 from their tapered seats in the grooves 69 after removing the nuts 74 from the hook bolts 71. Such loosening is readily accomplished merely by a sharp hammer blow applied on the top of the wedge 99.

At the rear end of the shroud 16, there is provided an adjustable spreader gate 100 whose lower edge 101 serves as a spreading lip for the pulverized materials. As seen specially in Figs. 5 and 8, the gate 100 is hinged at 102 by hinge means 104 to a shallow back wall 165 carried between the side walls of the shroud 16 and at the rear of the top wall 106 of such shroud. The gate 100 is adapted to be set and retained in such set position through the medium of a hydraulic jack which includes a cylinder 168 having projecting therefrom a piston rod 110 pivoted at 111 to a bracket 112 on the outer face of the gate 100, the upper end of the cylinder 108 being pivoted at 114 (Fig. l) to an overhanging bracket arm 115 fixed to the shroud walls 1615 and 106. Otherwise the gate may be arranged somewhat as seen in Fig. l.

In Figs. l2 and 13 there is illustrated a substantial modification of the pulverizing or disintcgrating rotor, at least from the standpoint of procedure. This diterence resides largely in the fact that the rotation of the rotor and its blades 65 which are carried on the rotor plates 60 is opposite to the direction of rotation of the forms of Figs. 5 and 8, inasmuch as in Fig. l2 the rotation is shown as clockwise so that the actuating edges 66 of the blades move toward the material being loosened, which movement at the point of contact with the material above the breaker bar assembly 75, 94 is in the same direction as the direction of travel of the apparatus, whereas in the arrangement of Figs. 5 and 8 such actuating edges 66 move counterclockwise to continue movement of the broken materials rearward or opposite to the direction of travel of the apparatus. In Fig. 12, a complete series of pulverizing blades 65 is illustrated, although the mounting of only one pair is indicated, and in this form only one pair of blades 65 is carried by a single pair of rotor plates 60 bound on the rotor shaft 42. With respect to the form of Figs. 12 and 13, it has been found that with some types of road-surfacing materials chunks of such materials are much more readily broken up if the pulverizing edges of the blades 65 are moved at a high rate of speed toward the roadsurfacing materials torn up, so that such chunks are repeatedly contacted until they are well disintegrated.

Since the resultant stream of materials must pass up over the rotor assembly, an arcuate retaining wall 120 is disposed above the rotor, the lower forward end of such wall 121i adjoining the rearward end of a transverse wall 122 spaced appreciably below the top wall of the shroud 16. Thus, disintegrated materials are moved by the blades 65 upward and under the arcuate wall 120 and thus moved toward the spreader gate 10i). Since the quantity of the broken materials is always being built up forward of the rotor while it moves in the clockwise direction shown, it is necessary to provide some form of stop wall or gate to receive such materials which otherwise might be thrown well forward under the entire apparatus. For this reason a series of heavy transversely disposed swinging plates 124 is provided as seen especially in Fig. 13. There may be for example three or four of such plates across the width of a full-sized road-working device. To the upper edges of these plates appropriate ears 125 are secured and to the under side of the overlying wall 122 a series of depending brackets 126 is secured, these ears and brackets receiving a transverse pivoting rod 128. Thus, the heavy gate members 124 limit the forward travel of the materials being pulverized and, being suiiiciently heavy, serve generally to maintain a body thereof subject to the high speed operation of the advancing ends 66 of the blades 65. Should large pieces of any type of material or any large object be moved against the forward faces of the stop plates 124, they will swing rearward so as to pass such pieces to the disintegrating blades, the arc of swing of the blades 124 being such that their lower edges will never contact the blades 65. With this particular form of structure, for many types of road-surfacing materials, the disintegrated product formed is in optimum condition for resurfacing. Here the upper and rearward edges of the breaker bar 75 and its cutter bar 94 lie substantially in vertical alignment with the center of the rotor shaft 42, or slightly rearward thereof.

Operation In preparing for operation of the pulverizing structure of this improvement, the pulverizing blades 65 of all forms are wedged into the described positions on their supporting heads 70 of the rotor plates 60 and retained by means of the hook bolts 71 and their nuts 74. The square-cut operating edges or ends 66 of the bottom blades 65 engaging the broken materials are directed to move rearward with the engaged materials, or counterclockwise as indicated by the circumferential arrows in Figs. and 8, or to strike them in the opposite direction, or clockwise, as in Fig. 12. Similarly, the breaker bar assembly 75, with its cutter teeth 14 or cutter bar 94, is disposed beneath the rotor 15 as illustrated in Figs. 5, 8 and l2, the position being such that the broken roadsurfacing material is raised by such breaker bar assembly 75 to the desired operating position. The position of the wheels 12 of the apparatus with respect to the surface of the road to be treated, and the relative position of the breaker bar assembly 75 with respect to the old road surfacing, are properly adjusted through the medium of the hydraulic jacks I, as best indicated in Fig. 1. The depth of cut and the new surface level to be established having been determined, the spreader lip 101 and the spreader gate are then set at the desired elevation through the medium of the hydraulic jack 108. The apparatus as a whole is then drawn forward in the direction of the long arrows at the left of Figs. 5, 8 and 12, and the rotor is driven at the relatively high rate indicated above so as to advance the cutting ends 66 of the pulverizing blades 65 rearward to engage, crush,

pick up and throw rearward the old road surfacing ma` terials as indicated in Figs. 5 and 8, or to strike and tumble them and carry them over the top of the rotor as seen in Fig. 12. The high speed action of the rotor 15 and its pulverizing blades 65 results in comparatively fineV subdivision of the old road-surfacing materials being handled, so that the body of such pulverized material caught between the side walls of the shroud and positioned by the gate is evenly distributed at any new surface line. These pulverized materials having been respread as shown may then be sprayed or otherwise treated with such new road-making materials Aas required,

such treated bed being again worked by the described apparatus for proper mixing and blending, and beingV again spread at a new level desired, following which the new bed may then be rolled or otherwise compacted.

It will be appreciated that by any of the above meansY the old, original road foundation on which the old surfacing materials were placed is not significantly disturbed and the reworked road-surfacing composition is properly deposited upon the old foundation whichV is thus continued in use. It will also be appreciated that, by arranging the breaker bar assembly beneath the rotor 15 as." indicated, there is a direct pulverizing coaction between'j the rotor 15 and the breaker bar assembly 75 so that the old'road-surfacing material is torn up and pulverized in a single operation directly below the rotor 15, such material being immediately discharged and respread. When breaker or cutter teeth 14 or pulverizing blades 65 be-v come unduly worn, or require replacement for any other reason, they may be readily removed and new elements substituted. Similarly, the transverse cutter bar 94 of Figs. 4, 4A and 12, may be reversed or replaced as Wear the direction of rotation; a plurality of tangential heads carried by said rotor and receiving said blades, said heads and blades having interlocking wedging tongue and socket means mounting said blades on said heads; and tie means retaining said blades on said heads by said4 wedging mounting means and including hook bolts mounted in said heads and having hook means engaged in pockets inl said blades and means connected with said', bolts to tension said hook means and bind said blades and heads together in wedging connection. y

2. A combination as in claim 1 including breaker means transversely underlying said rotor for raising broken road surfacing materials into position to be further broken by the cutting edges of said blades. A

3. A rotary blade assembly for a road-working implement including: a tangentially directed head, said head having a tangentially directed tapering groove; a tangential blade having a tapering tongue wedging in said groove and a transverse cutting end for travel in a tangentially rotary direction, said blade having a pocket in its rearward portion, said head having an outstanding apertured member; and bolt means mounted in said outstanding member and having a portion held in said pocket to retain said blade.

4. An assembly as in claim 3 wherein said apertured member is disposed rearward of said blade to provide a wedge space between said member and the rear end of said blade to receive wedge means to dislodge said blade from said head.

5. In combination in road working apparatus: a frame adapted to be moved forwardly; a rotor mounted on and transversely of said frame on a horizontal axis of rotation; a breaker bar assembly carried by and extending transversely of said frame beneath said rotor and including a horizontal bar inclined upwardly to direct broken road surface material into position adjacent said rotor for disintegration of said material; tangential heads circumferentially carried by said rotor; pulverizing blades detachably carried by said heads and having transverse cutting edges directed in the direction of rotation of said rotor, said heads and blades having interlocking wedging tongue 4and socket means to mount said blades on said heads; and tie means carried by said heads and connected to said blades to retain said blades on said heads in wedging relationship, said tie means including hook bolts mounted in said heads and hook means carried by said hook bolts and engaged in pockets in said blades,

References Cited in the file of this patent tionship in said heads.

UNITED STATES PATENTS Reinking Oct. 20, 1931 McHale Aug. 16, 1932 Davis Jan. 30, 1934 Gardner Aug. 17, 1937 Fink Apr. 7, 1942 Seaman Jan. 30, 1945 Murphy Sept. 18, 1945 Taylor Feb. 25, 1947 Hite Jan. 23, 1951 Small Sept. 7, 1954 

